title: New approach toward reflective films and fibers using cholesteric liquid-crystal coatings.
abstract: A new approach for the production of oriented films and fibers with angular-dependent reflective colors is presented. The process consists of spray coating a solution of cholesteric liquid-crystalline monomers onto a melt-processed and oriented polyamide-6 substrate followed by UV curing. Reflectivity measurements and optical microscopy show that a well-defined liquid-crystalline and planar alignment is obtained. It is further demonstrated that a reflection up to 80% is obtained by coating oriented films on both sides of the oriented substrate with a single-handedness cholesteric liquid-crystal coating. The high reflectivity is attributed to the close to half-wave retardation induced by the anisotropic polymer substrate. Also, polyamide-6 filaments are successfully coated and fibers are obtained with an angular-dependent color in a single dimension along the fiber direction, which originates from the planar cholesteric alignment on a curved surface.
authors.affiliation: School of Engineering and Materials Science, Queen Mary University of London, Mile End Road, London E1 4NS, U.K. o.t.picot@qmul.ac.uk
authors.forename: Olivier T
authors.initials: OT
authors.lastname: Picot
authors.forename: Mian
authors.initials: M
authors.lastname: Dai
authors.forename: Dirk J
authors.initials: DJ
authors.lastname: Broer
authors.forename: Ton
authors.initials: T
authors.lastname: Peijs
authors.forename: Cees W M
authors.initials: CW
authors.lastname: Bastiaansen